title: Sensitivity of methanotrophic community structure, abundance, and gene expression to CH4 and O2 in simulated landfill biocover soil.
abstract: Pressure on mitigating CH4 emission in landfill requires better understanding of methanotrophs in landfill biocovers. Most previous studies focused on CH4 as the sole substrate. This study aims to understand the sensitivity of methanotrophs to both substrates CH4 and O2 concentrations in landfill biocovers. The estimated CH4 oxidation rates (4.66-98.7 × 10(-16) mol cell(-1) h(-1)) were evidently higher than the previous reports, suggesting that activity of methanotrophs was enhanced with both the increasing of O2 and CH4 concentrations. Denaturing gradient gel electrophoresis based on the amplification of pmoA genes suggested that methanotrophs were more sensitive to CH4 than O2. Quantification of methanotrophs using pmoA- and mmoX-targeted real-time polymerase chain reaction showed that Mbac and Mcoc as well as Mcys groups were significantly dominant. Mbac group with pmoA gene transcription was dominant. Results indicate that CH4 mitigation would have higher potential by increasing O2 at appropriate CH4 concentrations.
authors.affiliation: Key Lab of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Huai
authors.initials: H
authors.lastname: Li
authors.forename: Zifang
authors.initials: Z
authors.lastname: Chi
authors.forename: Wenjing
authors.initials: W
authors.lastname: Lu
authors.forename: Hongtao
authors.initials: H
authors.lastname: Wang
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000378:metabolism*; D015870:Gene Expression; D008697:Methane / Q000032:analysis / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D010802:Phylogeny; D012037:Refuse Disposal; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D064091:Waste Disposal Facilities
chemical_list: D000393:Air Pollutants; D012987:Soil; D012989:Soil Pollutants; D008697:Methane; D010100:Oxygen
keywords: Cell CH(4) oxidation rate; Denaturing gradient gel electrophoresis (DGGE); Landfill biocover; Methanotrophs; Real time-polymerase chain reaction (real time-PCR)